It depends on what everyone else on the network is doing, there is no more precise answer that we can give you than the one that has been given. 10 different people will tell you 10 different things they think is the most efficient, and the information that could prove any one of them right changes quite literally every block.
What I need is a bunch of suggestion, then, I have to find out the most appropriate one for my case.
I have to do it certainly.
I just need help with your experience.
In my experience, it doesn't make a difference. But, if you want a specific size to make your inputs, make them somewhere between 500 Bulwark and 1000 Bulwark. The network average is somewhere around there, and it seems to be working well for them.